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51.
Overcoming the constraints of long range radio telemetry from animals: getting more useful data from smaller packages 总被引:2,自引:1,他引:1
Many species carry out their most interesting activities wherethey cannot readily be observed or monitored. Marine mammalsare extreme among this group, accomplishing their most astoundingactivities both distant from land and deep in the sea. Collection,storage and transmission of data about these activities areconstrained by the energy requirements and size of the recordingloggers and transmitters. The more bits of information collected,stored and transmitted, the more battery is required and thelarger the tag must be. We therefore need to be selective aboutthe information we collect, while maintaining detail and fidelity.To accomplish this in the study of marine mammals, we have designed"intelligent" data logger/transmitters that provide context-drivendata compression, data relay, and automated data base storage.We later combine these data with remotely sensed environmentalinformation and other oceanographic data sets to recreate theenvironmental context for the animal's activity, and we displaythe combined data using computer animation techniques. In thisway, the system can provide near real time "observation" ofanimal behavior and physiology from the remotest parts of theglobe. 相似文献
52.
Schizosaccharomyces pombe Git7p,a member of the Saccharomyces cerevisiae Sgtlp family,is required for glucose and cyclic AMP signaling,cell wall integrity,and septation 下载免费PDF全文
53.
Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising. 相似文献
54.
Candidatus "Scalindua brodae", sp. nov., Candidatus "Scalindua wagneri", sp. nov., two new species of anaerobic ammonium oxidizing bacteria 总被引:1,自引:0,他引:1
Schmid M Walsh K Webb R Rijpstra WI van de Pas-Schoonen K Verbruggen MJ Hill T Moffett B Fuerst J Schouten S Damsté JS Harris J Shaw P Jetten M Strous M 《Systematic and applied microbiology》2003,26(4):529-538
Anaerobic ammonium oxidation (anammox) is both a promising process in wastewater treatment and a long overlooked microbial physiology that can contribute significantly to biological nitrogen cycling in the world's oceans. Anammox is mediated by a monophyletic group of bacteria that branches deeply in the Planctomycetales. Here we describe a new genus and species of anaerobic ammonium oxidizing planctomycetes, discovered in a wastewater treatment plant (wwtp) treating landfill leachate in Pitsea, UK. The biomass from this wwtp showed high anammox activity (5.0 +/- 0.5 nmol/mg protein/min) and produced hydrazine from hydroxylamine, one of the unique features of anammox bacteria. Eight new planctomycete 16S rRNA gene sequences were present in the 16S rRNA gene clone library generated from the biomass. Four of these were affiliated to known anammox 16S rRNA gene sequences, but branched much closer to the root of the planctomycete line of descent. Fluorescence in situ hybridization (FISH) with oligonucleotide probes specific for these new sequences showed that two species (belonging to the same genus) together made up > 99% of the planctomycete population which constituted 20% of the total microbial community. The identification of these organisms as typical anammox bacteria was confirmed with electron microscopy and lipid analysis. The new species, provisionally named Candidatus "Scalindua brodae" and "Scalindua wagneri" considerably extend the biodiversity of the anammox lineage on the 16S rRNA gene level, but otherwise resemble known anammox bacteria. Simultaneously, another new species of the same genus, Candidatus "Scalindua sorokinii", was detected in the water column of the Black Sea, making this genus the most widespread of all anammox bacteria described so far. 相似文献
55.
Noel MB VanHeest JL Zaneteas P Rodgers CD 《Journal of strength and conditioning research / National Strength & Conditioning Association》2003,17(2):228-237
This study assessed body composition of Division I football players (n = 69) and compared the findings with previously reported data to ascertain whether the increase in player total body mass that has been observed over the past 10 years has been accompanied by an increase in body fat. Body composition was determined by hydrostatic weighing and the measurement of skinfold thicknesses. Total body mass, skinfold thicknesses, and body fat were greater in the current players than in players in studies conducted in the early 1980s and early 1990s. Body fat varied significantly across playing position, with the defensive backs, offensive backs, and receivers being the leanest and the offensive linemen and tight ends the most fat. There was no significant relationship between body composition and playing year or scholarship status, nor were any differences observed between ethnic groups. Of important clinical relevance was the finding that the linemen (offensive, defensive) and tight ends were on average greater than 25% body fat, the borderline for obesity in this age group. Much of this fat was deposited in the abdominal region, a significant finding when one considers the high correlation between abdominal obesity and ischemic heart disease and stroke. The current findings suggest that more attention needs to be given to the nature of the increase in body mass being achieved by today's football player to minimize long-term negative health consequences, and the findings reemphasize the need identified in earlier studies of the importance of detraining programs for these athletes. 相似文献
56.
Neuropathology of human Alzheimer disease after immunization with amyloid-beta peptide: a case report 总被引:25,自引:0,他引:25
Amyloid-beta peptide (Abeta) has a key role in the pathogenesis of Alzheimer disease (AD). Immunization with Abeta in a transgenic mouse model of AD reduces both age-related accumulation of Abeta in the brain and associated cognitive impairment. Here we present the first analysis of human neuropathology after immunization with Abeta (AN-1792). Comparison with unimmunized cases of AD (n = 7) revealed the following unusual features in the immunized case, despite diagnostic neuropathological features of AD: (i) there were extensive areas of neocortex with very few Abeta plaques; (ii) those areas of cortex that were devoid of Abeta plaques contained densities of tangles, neuropil threads and cerebral amyloid angiopathy (CAA) similar to unimmunized AD, but lacked plaque-associated dystrophic neurites and astrocyte clusters; (iii) in some regions devoid of plaques, Abeta-immunoreactivity was associated with microglia; (iv) T-lymphocyte meningoencephalitis was present; and (v) cerebral white matter showed infiltration by macrophages. Findings (i)-(iii) strongly resemble the changes seen after Abeta immunotherapy in mouse models of AD and suggest that the immune response generated against the peptide elicited clearance of Abeta plaques in this patient. The T-lymphocyte meningoencephalitis is likely to correspond to the side effect seen in some other patients who received AN-1792 (refs. 7-9). 相似文献
57.
Kwaks TH Barnett P Hemrika W Siersma T Sewalt RG Satijn DP Brons JF van Blokland R Kwakman P Kruckeberg AL Kelder A Otte AP 《Nature biotechnology》2003,21(5):553-558
The expression of transgenic proteins is often low and unstable over time, a problem that may be due to integration of the transgene in repressed chromatin. We developed a screening technology to identify genetic elements that efficiently counteract chromatin-associated repression. When these elements were used to flank a transgene, we observed a substantial increase in the number of mammalian cell colonies that expressed the transgenic protein. Expression of the shielded transgene was, in a copy number-dependent fashion, substantially higher than the expression of unprotected transgenes. Also, protein production remained stable over an extended time period. The DNA elements are small, not exceeding 2,100 base pairs (bp), and they are highly conserved between human and mouse, at both the functional and sequence levels. Our results demonstrate the existence of a class of genetic elements that can readily be applied to more efficient transgenic protein production in mammalian cells. 相似文献
58.
1. AMPA receptor potentiators (ARPs) exhibit antidepressant-like activity in preclinical tests (for example, the forced swim test) that are highly predictive of efficacy in humans. Unlike most currently used antidepressants, ARPs do not elevate extracellular levels of biogenic amines (e.g., 5HT, NE) in prefrontal cortex at doses that are active in the forced swim test.2. The present series of experiments examined the effects of combining the ARP, LY 392098, with biogenic amine-based antidepressants in the forced swim test. Male, NIH Swiss mice were placed in a cylinder of water and observed for attempted escape behaviors and immobility.3. LY 392098 dose-dependently decreased immobility as did a range of classical antidepressants. At doses of LY 392098 below those that decreased immobility, this compound significantly increased the potency with which fluoxetine and citalopram (SSRI antidepressants), imipramine (tricyclic antidepressant), duoxetine (norepinephrine/serotonin uptake blocker), nisoxetine (norepinephrine uptake inhibitor), and rolipram (PDE4 inhibitor) decreased immobility in the forced swim test with potency shifts upward of 5-fold (fluoxetine, imipramine, and rolipram). Likewise, ineffective doses of the traditional antidepressants potentiated the effects LY 392098 with shifts in the dose-effect functions that were 10-fold or more for citalopram, fluoxetine, imipramine, and duloxetine.4. Combined with other evidence for a role of AMPA receptors in the efficacy of antidepressants, the current data suggest that the addition of an ARP may augment the activity and perhaps the onset of the therapeutic effects of biogenic amine and second messenger-based antidepressants. 相似文献
59.
60.
Gary A. Flynn Ann L. Akeson Ram Dharanipragada Michael J. Genin J. Antony Malikayil Richard Pottorf Jeffery S. Sabol Herman Schreuder Ron Tomlinson Phil Waid Ron Barrett Jeff Jacobs Steve Yanofsky 《Letters in Peptide Science》1998,5(2-3):93-100
A collection of complementary peptide caricatures that closely mimic low-energy (presumably highly populated) conformations of amino acids of interest would constitute a valuable tool set to study the interactions of small peptide ligands with their biological targets. Our general strategy for the design, synthesis and application of peptidomimetics is presented. An illustration of how structural information from mimetics combined with cutting edge biophysical data can be used to derive a model for the bound conformation of an 11-mer peptide antagonist with the IL-1 receptor is given. 相似文献